JPH03212523A - Running speed switching device for hydraulic excavator - Google Patents
Running speed switching device for hydraulic excavatorInfo
- Publication number
- JPH03212523A JPH03212523A JP2009762A JP976290A JPH03212523A JP H03212523 A JPH03212523 A JP H03212523A JP 2009762 A JP2009762 A JP 2009762A JP 976290 A JP976290 A JP 976290A JP H03212523 A JPH03212523 A JP H03212523A
- Authority
- JP
- Japan
- Prior art keywords
- travel
- control
- hydraulic pump
- hydraulic
- speed
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000003921 oil Substances 0.000 description 19
- 230000007423 decrease Effects 0.000 description 8
- 238000010586 diagram Methods 0.000 description 6
- 238000011144 upstream manufacturing Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 3
- 238000006073 displacement reaction Methods 0.000 description 2
- 239000010720 hydraulic oil Substances 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/20—Drives; Control devices
- E02F9/22—Hydraulic or pneumatic drives
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
- F16H61/38—Control of exclusively fluid gearing
- F16H61/40—Control of exclusively fluid gearing hydrostatic
- F16H61/4148—Open loop circuits
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/20—Drives; Control devices
- E02F9/22—Hydraulic or pneumatic drives
- E02F9/2253—Controlling the travelling speed of vehicles, e.g. adjusting travelling speed according to implement loads, control of hydrostatic transmission
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
- F15B11/02—Systems essentially incorporating special features for controlling the speed or actuating force of an output member
- F15B11/04—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed
- F15B11/044—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed by means in the return line, i.e. "meter out"
- F15B11/0445—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed by means in the return line, i.e. "meter out" with counterbalance valves, e.g. to prevent overrunning or for braking
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
- F16H61/38—Control of exclusively fluid gearing
- F16H61/40—Control of exclusively fluid gearing hydrostatic
- F16H61/42—Control of exclusively fluid gearing hydrostatic involving adjustment of a pump or motor with adjustable output or capacity
- F16H61/423—Motor capacity control by fluid pressure control means
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
- F16H61/38—Control of exclusively fluid gearing
- F16H61/40—Control of exclusively fluid gearing hydrostatic
- F16H61/42—Control of exclusively fluid gearing hydrostatic involving adjustment of a pump or motor with adjustable output or capacity
- F16H61/433—Pump capacity control by fluid pressure control means
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
- F16H61/38—Control of exclusively fluid gearing
- F16H61/40—Control of exclusively fluid gearing hydrostatic
- F16H61/46—Automatic regulation in accordance with output requirements
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
- F16H61/38—Control of exclusively fluid gearing
- F16H61/40—Control of exclusively fluid gearing hydrostatic
- F16H61/46—Automatic regulation in accordance with output requirements
- F16H61/47—Automatic regulation in accordance with output requirements for achieving a target output speed
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
- F15B2211/205—Systems with pumps
- F15B2211/2053—Type of pump
- F15B2211/20546—Type of pump variable capacity
- F15B2211/20553—Type of pump variable capacity with pilot circuit, e.g. for controlling a swash plate
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/30—Directional control
- F15B2211/305—Directional control characterised by the type of valves
- F15B2211/30505—Non-return valves, i.e. check valves
- F15B2211/30515—Load holding valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/30—Directional control
- F15B2211/31—Directional control characterised by the positions of the valve element
- F15B2211/3122—Special positions other than the pump port being connected to working ports or the working ports being connected to the return line
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/50—Pressure control
- F15B2211/505—Pressure control characterised by the type of pressure control means
- F15B2211/50509—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means
- F15B2211/50545—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means using braking valves to maintain a back pressure
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/50—Pressure control
- F15B2211/515—Pressure control characterised by the connections of the pressure control means in the circuit
- F15B2211/5153—Pressure control characterised by the connections of the pressure control means in the circuit being connected to an output member and a directional control valve
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/60—Circuit components or control therefor
- F15B2211/605—Load sensing circuits
- F15B2211/6051—Load sensing circuits having valve means between output member and the load sensing circuit
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/60—Circuit components or control therefor
- F15B2211/605—Load sensing circuits
- F15B2211/6058—Load sensing circuits with isolator valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/60—Circuit components or control therefor
- F15B2211/67—Methods for controlling pilot pressure
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
- F15B2211/705—Output members, e.g. hydraulic motors or cylinders or control therefor characterised by the type of output members or actuators
- F15B2211/7058—Rotary output members
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
- F15B2211/71—Multiple output members, e.g. multiple hydraulic motors or cylinders
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
- F15B2211/75—Control of speed of the output member
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は油圧掘削機の走行速度切換装置に関し、特に、
走行速度を三段以上に切換可能とすることにより、路面
状況及び作業状況に応じて最適な走行速度を選択し易く
すると共に、作業機の微操作時における同時操作性の向
上を図ることを目的とする油圧掘削機の走行速度切換装
置に関する。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a traveling speed switching device for a hydraulic excavator, and in particular,
By making it possible to switch the travel speed into three or more stages, the purpose is to make it easier to select the optimal travel speed depending on the road surface condition and work situation, and to improve simultaneous operability when making small adjustments to the work equipment. The present invention relates to a travel speed switching device for a hydraulic excavator.
（従来の技術）
従来、油圧掘削機の走行速度は第３図に示されるように
、油圧ポンプ５１の吐出油を左右の走行操作弁５２ ａ
、 ５２ ｂにより制御してスイベルジヨイント５３
を経て左右の走行モータ５４ａ、５４ｂへ供給すること
によって制御している。第３図において走行速度切換ス
イッチ５５を１遼に設定すると、制御圧切換弁５６のソ
レノイド５６ａが消磁されるため、制御圧切換弁５６は
ａ位置となる。従って、左右の走行モータ５４ａ、５４
ｂの走行速度切換弁５８ａ、５８ｂのパイロットシリン
ダ５９ ａ、 ５９ ｂはスイベルジヨイント５３を経
て、制御圧切換弁５６からタンクへ接続されるため、走
行速度切換弁５８ａ、５８ｂはａ位置となる。その結果
、走行モータ容量制御シリンダ６０ａ、６０ｂはタンク
１０に接続されるため、左右の走行モータ５４ａ、５４
ｂの容量が増し、１遠の走行速度段となる。次に、図示
しない走行操作レバーによって、走行操作弁５２ ａ、
５２ ｂをそれぞれａ位置に操作すると、油圧ポン
プ５１の吐出油は左右の走行モータ５４ａ、５４ｂの駆
動管路６１ａ、６１ｂを経て左右の走行モータ５４ａ、
５４ｂへ供給され、走行モータ５４ａ、５４ｂから排出
管路６２ａ、６２ｂへ排出されるが、カウンタバランス
弁６３ａ、６３ｂは前記駆動管路６１ａ、６１ｂの作動
油圧によってそれぞれａ位置となっているため、前記排
出管路６２ａ、６２ｂへ排出された作動油はカウンタバ
ランス弁６３ａ、６３ｂを経てスイベルジヨイント５３
、走行操作弁５２ ａ、 ５２ ｂを経て、図示しな
い戻り管路からタンク７０に戻される。従って、左右の
走行モータ５４ａ、５４ｂは１遠の走行速度段により、
前記走行操作レバーの操作量に応じた回転数で回転する
ため、該回転数に応じた速度で車両を前進または後進さ
せることができる。なお、前記走行操作弁５２ａ、５２
ｂのａ位置を車両の前進方向とすればｂ位置は車両の後
進方向となるが前記車両の前進方向と同様のため、作用
の説明は省略する。また、６４はロードセンシング弁で
、該ロードセンシング弁６４の＄１パイロット室６４ｂ
には油圧ポンプ５１の吐出油が導かれ、第２パイロット
室６４ｃには前記走行操作弁５２ａ５２ｂおよびチエツ
ク弁６５ａ、６５ｂにより走行モータ５４ａ、５４ｂの
駆動管路６１ａ。(Prior Art) Conventionally, as shown in FIG. 3, the running speed of a hydraulic excavator is determined by controlling the oil discharged from the hydraulic pump 51 by controlling the left and right running operation valves 52a.
, 52 b to control the swivel joint 53
Control is performed by supplying the power to the left and right travel motors 54a and 54b through the motors 54a and 54b. In FIG. 3, when the traveling speed changeover switch 55 is set to 1, the solenoid 56a of the control pressure changeover valve 56 is demagnetized, so that the control pressure changeover valve 56 is in the a position. Therefore, the left and right traveling motors 54a, 54
Since the pilot cylinders 59a, 59b of the traveling speed switching valves 58a, 58b of b are connected from the control pressure switching valve 56 to the tank via the swivel joint 53, the traveling speed switching valves 58a, 58b are in the a position. . As a result, since the travel motor capacity control cylinders 60a, 60b are connected to the tank 10, the left and right travel motors 54a, 54
The capacity of b increases, and the traveling speed becomes 1 far. Next, by using a travel control lever (not shown), travel control valves 52 a,
52b to the a position, the oil discharged from the hydraulic pump 51 passes through the drive pipes 61a, 61b of the left and right travel motors 54a, 54b, and then flows to the left and right travel motors 54a, 54b.
54b, and is discharged from the travel motors 54a, 54b to exhaust pipes 62a, 62b, but since the counterbalance valves 63a, 63b are at the a position due to the hydraulic pressure of the drive pipes 61a, 61b, respectively, The hydraulic oil discharged to the discharge pipes 62a, 62b passes through the counterbalance valves 63a, 63b to the swivel joint 53.
, traveling operation valves 52 a and 52 b, and is returned to the tank 70 from a return pipe (not shown). Therefore, the left and right traveling motors 54a, 54b are driven by the 1 farthest traveling speed stage.
Since it rotates at a rotational speed that corresponds to the amount of operation of the travel control lever, the vehicle can be moved forward or backward at a speed that corresponds to the rotational speed. Note that the travel operation valves 52a, 52
If position a of b is taken as the forward direction of the vehicle, position b becomes the backward direction of the vehicle, but since it is the same as the forward direction of the vehicle, a description of the operation will be omitted. Further, 64 is a load sensing valve, and the $1 pilot chamber 64b of the load sensing valve 64 is
The discharge oil of the hydraulic pump 51 is introduced into the second pilot chamber 64c, and the driving conduit 61a of the traveling motors 54a, 54b is connected to the traveling operation valve 52a52b and the check valves 65a, 65b.
６１ｂの内、高い方の負荷圧が導かれ、これら第１パイ
ロット室６４ｂの推力と、第２パイロット室６４ｃの推
力およびばね６４ａのばね力とが常に釣り合うように油
圧ポンプ５１の吐出油圧を減圧して油圧ポンプ５１の容
量制御シリンダ５１ａを制御するように作用する。即ち
、前記走行操作弁５２ａ、５２ｂの上流と下流には常に
ロードセンシング弁６４のばね６４ａのばね力に相当す
る差圧が生ずるようにして、油圧ポンプ５１の吐出油量
を走行操作弁５２ ａ、 ５２ ｂの操作量に応じて
増減するように制御している。また、２遼の走行速度段
については、走行速度切換スイッチ５５を２遠に設定す
ると、制御圧切換弁５６のソレノイド５６ａが励磁され
るため、制御圧切換弁５６はｂ位置となる。従って、左
右の走行モータ５４ａ、５４ｂの走行速度切換弁５８ａ
、５８ｂのパイロットシリンダ５９ａ、５９ｂはスイベ
ルジヨイント５３を介して制御ポンプ５７に接続される
ため、走行速度切換弁５８ａ、５８ｂはｂ位置となる。61b is introduced, and the discharge hydraulic pressure of the hydraulic pump 51 is reduced so that the thrust of the first pilot chamber 64b, the thrust of the second pilot chamber 64c, and the spring force of the spring 64a are always balanced. It acts to control the capacity control cylinder 51a of the hydraulic pump 51. That is, a pressure difference corresponding to the spring force of the spring 64a of the load sensing valve 64 is always generated between the upstream and downstream sides of the traveling operation valves 52a and 52b, so that the amount of oil discharged from the hydraulic pump 51 is controlled by the traveling operation valve 52a. , 52b are controlled to increase or decrease according to the manipulated variables. In addition, for the traveling speed stage of 2 Liao, when the traveling speed changeover switch 55 is set to 2-way, the solenoid 56a of the control pressure changeover valve 56 is energized, so that the control pressure changeover valve 56 is in the b position. Therefore, the running speed switching valve 58a of the left and right running motors 54a, 54b
, 58b are connected to the control pump 57 via the swivel joint 53, so the travel speed switching valves 58a, 58b are at position b.
その結果、走行モータ容量制御シリンダ６０ａ、６０ｂ
には左右の走行モータ５４ａ、５４ｂの駆動油圧が供給
されるため、左右の走行モータ５４ａ、５４ｂの容量が
減少し、２遼の走行速度段となる。走行操作弁５２ａ、
５２ｂの操作による作用については前記ｌ遠の走行速度
段の場合と同様のため説明を省略する。As a result, the travel motor capacity control cylinders 60a, 60b
Since the driving oil pressure for the left and right traveling motors 54a and 54b is supplied to the left and right traveling motors 54a and 54b, the capacities of the left and right traveling motors 54a and 54b are reduced, resulting in a traveling speed stage of 2. Travel operation valve 52a,
The effect of the operation of 52b is the same as in the case of the 1-far travel speed gear described above, so a description thereof will be omitted.
（発明が解決しようとする課題） 前記従来の技術においては、走行モータ５４ａ。(Problem to be solved by the invention) In the prior art, the travel motor 54a.
５４ｂの走行速度段が二段切換であるため、高速段と低
速段を、作業状況、路面状況に最適な速度段に設定する
と速度差が大きくなり過ぎ、高速段または低速段の一方
を最適な速度に設定すると他方の速度が早すぎたり遅す
ぎることとなり、オペレータが作業状況、路面状況に応
じて最適な速度段を選びにくいという問題があった。ま
た、一般に車両走行中には油圧ポンプ５１の吐出油量が
最大となるように設定されるため、車両走行中に作業機
を操作すると、例え微操作であっても車両の走行速度が
低下し、荷揺れ等の発生により同時操作性が低下すると
いう欠点があった。54b's running speed is a two-speed switch, so if the high speed and low speed are set to the speed that is most suitable for the work situation and road surface condition, the speed difference will become too large, and it is necessary to set either the high or low speed to the optimal speed. If one speed is set, the other speed will be too fast or too slow, making it difficult for the operator to select the optimal speed stage depending on the work situation and road surface condition. In addition, since the amount of oil discharged from the hydraulic pump 51 is generally set to be maximum while the vehicle is running, operating the work equipment while the vehicle is running, even if it is a small operation, will reduce the running speed of the vehicle. However, there was a drawback in that simultaneous operability was reduced due to the occurrence of load shaking, etc.
（課題を解決するための手段）
本発明は前記従来の技術における課題を解決するために
なされたもので、油圧ポンプの吐出油を左右の走行操作
弁により制御して、左右の走行モータへ供給するように
なし、前記油圧ポンプの容量制御シリンダの制御圧をコ
ントロールするロードセンシング弁の第１パイロット室
に前記油圧ポンプの吐出油圧を導くと共に、第２パイロ
ット室に走行モータの駆動圧を導き、これら第１パイロ
ット室の推力と、第２パイロ７ト室の推力および差圧設
定ばねのばね力との釣り合いによって、前記油圧ポンプ
の容量制御シリンダの制御圧をコントロールするように
した油圧掘削機の走行速度制御装置において、複数の走
行速度段を得るために、前記差圧設定ばねのセット力を
複数段に切換える差圧設定ばｂのセフ）力調整装置を設
けた。また前記差圧設定ばねの一つのセノトカについて
、走行モータの容量を二段に切換えるために走行モータ
の容量切換装置を設けたり、前記差圧設定ばねのセット
力調整装置あるいは走行モータの容量切換装置を、ソレ
ノイド弁により制御油圧源およびタンクに選択的に接続
するよう構成してもよい。(Means for Solving the Problems) The present invention has been made to solve the problems in the conventional technology, and the oil discharged from the hydraulic pump is controlled by the left and right travel control valves and supplied to the left and right travel motors. guiding the discharge hydraulic pressure of the hydraulic pump to a first pilot chamber of a load sensing valve that controls the control pressure of a displacement control cylinder of the hydraulic pump, and guiding the drive pressure of the travel motor to a second pilot chamber; A hydraulic excavator is provided in which the control pressure of the capacity control cylinder of the hydraulic pump is controlled by the balance between the thrust of the first pilot chamber, the thrust of the second pilot chamber, and the spring force of the differential pressure setting spring. In the traveling speed control device, in order to obtain a plurality of traveling speed stages, a differential pressure setting step (b) force adjustment device is provided for switching the setting force of the differential pressure setting spring to a plurality of stages. In addition, for one of the differential pressure setting springs, a travel motor capacity switching device may be provided to switch the capacity of the travel motor into two stages, a setting force adjustment device for the differential pressure setting spring, or a travel motor capacity switching device. may be configured to be selectively connected to the control hydraulic pressure source and tank by a solenoid valve.
（作用）
一般に操作弁を通過する油量Ｑは、操作弁の上流圧；Ｐ
Ｐと下流圧；ＰＬとの圧力差； Ｐ ｐ Ｐ Ｌ、お
よび操作弁の開度；Ａにより、ＱｏｃＡ−、／’−下Ｔ
：ＰＬ・・・・・ （１）と表すことができる。本発明
においては、走行操作弁の上流圧＋ Ｐ ｐは油圧ポン
プの吐出油圧、また、下流圧ｉ Ｐ Ｌは走行モータの
駆動圧であり、前記走行操作弁の上流圧；Ｐアと下流圧
ＰＬとの圧力差；ＰアーＰＬはロードセンシング弁の差
圧設定ばねのばね力；Ｆによって決定されるため、Ｑ（
Ｘ：Ａ−、／’１−・・・・・ （２）のような関係と
なる。即ち、Ｆを複数段に切換えるようにすれば、同じ
走行操作弁の操作量（開度）：Ａに対して複数段の油圧
ポンプ吐出量；Ｑ、言い換えれば、複数段の走行速度が
得られることになる。また、前記走行モータの容量を二
段に切換えるための走行モータ容量切換装置を設ければ
前記複数段の走行速度段は２倍になる。更に、前記油圧
掘削機の走行速度切換装置において、差圧設定ばねのセ
ット力調整装置あるいは走行モータ容量切換装置をソレ
ノイド弁により制御圧源あるいはタンクに選択的に接続
することによって走行速度を複数段に切り換えることが
できる。(Function) In general, the amount of oil Q passing through the operating valve is determined by the upstream pressure of the operating valve; P
P and downstream pressure; pressure difference with PL; P p P L, and the opening degree of the operation valve; A, QocA-, /'-lower T
:PL... It can be expressed as (1). In the present invention, the upstream pressure of the travel operation valve + P p is the discharge oil pressure of the hydraulic pump, and the downstream pressure i P is the drive pressure of the travel motor, and the upstream pressure of the travel operation valve; The pressure difference between PL and PL is determined by the spring force of the differential pressure setting spring of the load sensing valve; therefore, Q(
X: A-, /'1-... The relationship is as shown in (2). In other words, by switching F to multiple stages, it is possible to obtain multiple stages of hydraulic pump discharge amount Q for the same traveling operation valve operation amount (opening degree) A, in other words, multiple stages of travel speed. It turns out. Further, if a traveling motor capacity switching device for switching the capacity of the traveling motor into two stages is provided, the number of traveling speed stages of the plurality of stages can be doubled. Furthermore, in the travel speed switching device for the hydraulic excavator, the travel speed can be changed to multiple levels by selectively connecting the differential pressure setting spring set force adjustment device or the travel motor capacity switching device to the control pressure source or tank through a solenoid valve. You can switch to .
（実施例）
以下に本発明の実施例につき、添付図面を参照して詳述
する。油圧掘削機の走行速度は、第１図に示されるよう
に、油圧ポンプ１の吐出油を左右の走行操作弁２ａ、２
ｂによって制御してスイベルジヨイント３を経て左右の
走行モータ４ａ１４ｂへ供給することによって制御して
いる。前記油圧掘削機の走行速度制御は具体的には次の
様にしてコントロールされる。まず、走行速度切換スイ
ッチ５を１速度段に設定すると、該走行速度切換スイッ
チ５の設定信号はコントローラ７を経て制御圧切換弁６
のソレノイド６ａを消磁するため、前記制御圧切換弁６
はａ位置となり、ばね力調整シノンダ９はタンクｌＯに
接続される。従って、ばね力調整シリンダ９内のばｂ
９ ａによりピストンロッド９ｂが左行してロードセン
シング弁１１の差圧設定ばねｌｌａのセット力−Ｆが減
少するため、前記（２）式１こおいて、走行操作弁２ａ
、２ｂの操作量（開度）；Ａが同一でも油圧ポンプｌの
吐出油量；Ｑは前記差圧設定ばねｌｌａのセット力；Ｆ
の減少分だけ減少するため、走行速度もその分減少する
。また同時に、前記走行速度切換スイッチ５の設定信号
はコントローラ７を経て制御圧切換弁１２のソレノイド
１２ａを消磁するため、前記制御圧切換弁１２はａ位置
となり、走行モータ容量切換弁１３ａ、１３ｂのパイロ
ットシリンダ１４ａ、１４ｂはタンク１ｏに連通する。(Example) Examples of the present invention will be described in detail below with reference to the accompanying drawings. As shown in FIG.
b, and is supplied to the left and right travel motors 4a14b via the swivel joint 3. Specifically, the traveling speed of the hydraulic excavator is controlled as follows. First, when the travel speed selector switch 5 is set to the 1st speed stage, the setting signal of the travel speed selector switch 5 is passed through the controller 7 to the control pressure selector valve 6.
In order to demagnetize the solenoid 6a, the control pressure switching valve 6
is at position a, and the spring force adjustment cylinder 9 is connected to the tank lO. Therefore, the spring in the spring force adjusting cylinder 9
9a causes the piston rod 9b to move to the left and the setting force -F of the differential pressure setting spring lla of the load sensing valve 11 decreases.
, 2b operation amount (opening degree); Even if A is the same, the amount of oil discharged from the hydraulic pump l; Q is the setting force of the differential pressure setting spring lla; F
Since the vehicle speed decreases by the same amount, the traveling speed also decreases by that amount. At the same time, the setting signal of the travel speed changeover switch 5 passes through the controller 7 and demagnetizes the solenoid 12a of the control pressure changeover valve 12, so the control pressure changeover valve 12 is in position a, and the travel motor capacity changeover valves 13a and 13b are Pilot cylinders 14a, 14b communicate with tank 1o.
従って、走行モータ容量切換弁１３ａ、１３ｂはａ位置
となり、走行モータ容量制御シリンダ１５ａ、１５ｂが
タンクに連通するため、左右の走行モータ４ａ、４ｂは
大容量に設定されて１遠度段で走行する。次に、走行速
度切換スイッチ５を２速度段に設定すると、該走行速度
切換スイッチ５の設定信号はコントローラ７を経て制御
圧切換弁６のソレノイド６ａを消磁するため、前記制御
圧切換弁６はａ位置となり、ばね力調整シリンダ９はタ
ンク１０に接続される。従って、ばね力調整シ、リンダ
９内のピストンロッド９ｂはばね９ａによって左行して
ロードセンシング弁１１の差圧設定ばねｌｌａのセット
カーＦが減少するため、前記（２）式において、走行操
作弁２ａ、２ｂの操作量（開度）；Ａが同一でも油圧ポ
ンプ１の吐出油量；Ｑは前記差圧設定ばねｌｌａのセッ
トカーＦの減少分だけ減少して走行遠度もその分減少す
る。また同時に、前記走行速度切換スイッチ５の設定信
号はコントローラ７を経て制御圧切換弁１２のソレノイ
ド１２ａを励磁するため、前記制御圧切換弁１２はｂ位
置となり、走行モータ容量切換弁１３ａ、１３ｂのパイ
ロットシリンダ１４ａ１４ｂは制御ポンプ８に接続され
る。従って、走行モータ容量切換弁１３ａ、１３ｂはｂ
位置となり、走行モータ容量制御シリンダ１５ａ、１５
ｂに走行モータの駆動圧が供給されるため、左右の走行
モータ４ａ、４ｂは大容量に設定されて２遼度段で走行
する。次に、走行速度切換スイッチ５を３速度段に設定
すると、該走行速度切換スイッチ５の設定信号はコント
ローラ７を経て制御圧切換弁６のソレノイド６ａを励磁
するため、前記制御圧切換弁６はｂ位置となり、ばね力
調整シリンダ９は制御ポンプ８に接続される。従って、
ばね力調整シリンダ９内のピストンロッド９ ｂ ＋ｉ
ｉｆね９ａのばね力に打ち勝って右行してロードセン
シング弁１１の差圧設定ばねｌｌａのセット力；Ｆを増
大するため、前記（２）式において、走行操作弁２ａ、
２ｂの操作量（開度）；Ａが同一でも油圧ポンプ１の吐
出油量；Ｑは前記差圧設定ばねｌｌａのセット力゛；Ｆ
の増大分だけ増加して走行速度もその分増加する。また
同時に、前記走行速度切換スイッチ５の設定信号はコン
トローラ７を経て制御圧切換弁１２のソレノイド１２ａ
を励磁するため、前記制御圧切換弁１２はｂ位置となり
、走行モータ容量切換弁１３ａ、１３ｂのバイロフトシ
リンダ１４ａ、１４ｂは制御ポンプ８に接続される。従
って、走行モータ容量切換弁１３ａ、１３ｂはｂ位置と
なり、走行モータ容量制御シリンダ１５ａ、１５ｂに走
行モータの駆動圧が供給されるため、左右の走行モータ
４ａ＋４ｂは小容量に設定されて３遠度段で走行する。Therefore, the travel motor capacity switching valves 13a, 13b are in the a position, and the travel motor capacity control cylinders 15a, 15b are communicated with the tank, so the left and right travel motors 4a, 4b are set to large capacity and travel in one far stage. do. Next, when the travel speed selector switch 5 is set to the second speed stage, the setting signal of the travel speed selector switch 5 passes through the controller 7 and demagnetizes the solenoid 6a of the control pressure selector valve 6. At position a, the spring force adjustment cylinder 9 is connected to the tank 10. Therefore, the spring force adjusting cylinder 9 moves the piston rod 9b in the cylinder 9 to the left by the spring 9a, and the set value F of the differential pressure setting spring lla of the load sensing valve 11 decreases. Even if the operation amount (opening degree) of the valves 2a and 2b is the same, the amount of oil discharged from the hydraulic pump 1; do. At the same time, the setting signal of the travel speed changeover switch 5 passes through the controller 7 and excites the solenoid 12a of the control pressure changeover valve 12, so that the control pressure changeover valve 12 is in position b, and the travel motor capacity changeover valves 13a and 13b are turned on. The pilot cylinder 14a14b is connected to the control pump 8. Therefore, the traveling motor capacity switching valves 13a and 13b are
position, and the travel motor capacity control cylinders 15a, 15
Since the driving pressure of the running motor is supplied to the drive motor 4b, the left and right running motors 4a and 4b are set to a large capacity and run at 2 liao speeds. Next, when the travel speed changeover switch 5 is set to the third speed stage, the setting signal of the travel speed changeover switch 5 passes through the controller 7 and excites the solenoid 6a of the control pressure changeover valve 6. At position b, the spring force adjustment cylinder 9 is connected to the control pump 8. Therefore,
Piston rod 9 b +i in spring force adjustment cylinder 9
In order to overcome the spring force of the if spring 9a and move to the right and increase the setting force;
2b operation amount (opening degree); even if A is the same, the amount of oil discharged from the hydraulic pump 1; Q is the setting force of the differential pressure setting spring lla; F
The travel speed increases accordingly. At the same time, the setting signal for the traveling speed changeover switch 5 is sent to the solenoid 12a of the control pressure changeover valve 12 via the controller 7.
In order to excite the motor, the control pressure switching valve 12 is in the b position, and the biloft cylinders 14a and 14b of the traveling motor capacity switching valves 13a and 13b are connected to the control pump 8. Therefore, the travel motor capacity switching valves 13a and 13b are in the b position, and the drive pressure of the travel motor is supplied to the travel motor capacity control cylinders 15a and 15b, so the left and right travel motors 4a+4b are set to a small capacity and 3 degrees out. Run in steps.
次に第１図に示す１遠度段の場合における走行操作につ
いて説明する。まず、図示しない走行操作レバーによっ
て、走行操作弁２ａ、２ｂをそれぞれａ位置に操作する
と、該操作量に応じた油圧ポンプ１の吐出油は左右の走
行モータ４ａ、４ｂの駆動管路１６ａ、１６ｂを経て左
右の走行モータ４ａ。Next, the traveling operation in the case of one far stage shown in FIG. 1 will be explained. First, when the travel operation valves 2a and 2b are operated to the a position by the travel operation levers (not shown), the oil discharged from the hydraulic pump 1 according to the operation amount is transferred to the drive pipes 16a and 16b of the left and right travel motors 4a and 4b. through the left and right travel motors 4a.
４ｂへ供給され、走行モータ４ａ、４ｂから排出管路１
８ａ、１８ｂへ排出されるが、カウンタバランス弁２０
ａ、 ２０ ｂは前記駆動管路１６ａ。4b, and from the travel motors 4a, 4b to the discharge pipe 1.
8a and 18b, but the counterbalance valve 20
a, 20b are the drive conduit 16a.
１６ｂの駆動油圧によってそれぞれａ位置となっている
ため、前記排出管路１８ａ、１８ｂへ排出された作動油
はカウンタバランス弁２０ａ、２０ｂを経てスイベルジ
ヨイント３、走行速度切換弁２、ａ、２ｂを経て、戻り
管路（図示せず）からタンク１０に戻される。従って、
左右の走行モータ４ａ、４ｂは前記走行操作レバーの操
作量に応じた回転数で回転するため、該回転数に応じた
速度で車両を前進または後進させることができる。なお
、前記走行操作弁２ａ、２ｂのａ位置を車両の前進方向
とすればｂ位置は車両の後進方向となるが、この場合の
作用については前記車両の前進方向と同様であるため、
説明を省略する。また、ロードセンシング弁１１の第１
パイロット室１１ｂには油圧ポンプｌの吐出油が導かれ
、第２パイロット室１１ｃには前記走行操作弁２ａ、２
ｂおよびチエツク弁２１ａ、２１ｂにより、走行モータ
４ａ、４ｂの駆動管路１６ａ、１６ｂの内、高圧の駆動
圧が導かれ、これら第１パイロット室ｌｌｂと第２パイ
ロット室１１ｃの差圧（差圧設定ばねｌｌａのセットカ
ーＦ）に応じて油圧ポンプ１の吐出油圧を減圧して油圧
ポンプ１の容量制御シＪンダｌａを制御するように作用
する。即ち、前記走行操作弁２ａ、２ｂの上流と下流に
は常にロードセンシング弁１１のばねｌｌａのばね力に
相当する差圧が生ずるようにして、油圧ポンプ】の吐出
油量は常に、走行操作弁２ａ、２ｂの操作量に応じて制
御される。16b are set at position a by the driving oil pressure, the hydraulic oil discharged to the discharge pipes 18a and 18b passes through the counterbalance valves 20a and 20b to the swivel joint 3 and the travel speed switching valves 2, a, and 2b. The water is then returned to the tank 10 through a return line (not shown). Therefore,
Since the left and right travel motors 4a and 4b rotate at a rotation speed that corresponds to the amount of operation of the travel control lever, the vehicle can be moved forward or backward at a speed that corresponds to the rotation speed. Note that if the a position of the travel control valves 2a, 2b is in the forward direction of the vehicle, the b position is in the backward direction of the vehicle, but the operation in this case is the same as in the forward direction of the vehicle.
The explanation will be omitted. In addition, the first load sensing valve 11
The discharge oil of the hydraulic pump l is introduced into the pilot chamber 11b, and the traveling operation valves 2a, 2 are introduced into the second pilot chamber 11c.
b and check valves 21a, 21b, high driving pressure is introduced into the drive lines 16a, 16b of the travel motors 4a, 4b, and the differential pressure (differential pressure) between the first pilot chamber llb and the second pilot chamber 11c is It acts to control the displacement control cylinder 1a of the hydraulic pump 1 by reducing the discharge hydraulic pressure of the hydraulic pump 1 in accordance with the set car F) of the setting spring 11a. That is, a pressure difference corresponding to the spring force of the spring lla of the load sensing valve 11 is always generated between the upstream and downstream of the traveling operation valves 2a and 2b, so that the amount of oil discharged from the hydraulic pump is always equal to the amount of oil discharged from the traveling operation valve. It is controlled according to the operating amounts of 2a and 2b.
次に、第２図について説明する。（ａ）は本発明におけ
る油圧ポンプの吐出量Ｑと負荷圧Ｐとの関係を示す図で
、表１に示されあように、１速度段と２速度段において
は油圧ポンプｌの吐出量が最大８０％に設定されている
ため、走行中に作業機を操作しても、油圧ポンプ１の吐
出量は後２０％余裕があるため、作業機に必要な吐出量
だけ油圧ポンプ１の吐出量を増加して、走行速度を低下
するようなことがなく、同時操作性を向上させることが
できる。Next, FIG. 2 will be explained. (a) is a diagram showing the relationship between the discharge amount Q of the hydraulic pump and the load pressure P in the present invention. As shown in Table 1, the discharge amount of the hydraulic pump l is Since it is set to a maximum of 80%, even if you operate the work equipment while driving, the discharge amount of the hydraulic pump 1 has a margin of 20%, so the discharge amount of the hydraulic pump 1 will be reduced by the amount required for the work equipment. It is possible to increase the simultaneous operability without reducing the running speed.
表１
（ｂ）および（ｃ）は従来の技術を示す図で、（ｂ）の
ように油圧ポンプｌの吐出量を左右の走行モータ４ａ、
４ｂに５０％づつ供給している状態で、（Ｃ）のように
作業機を操作して、油圧ポンプ１の吐出量の２０％を供
給すれば、左右の走行モータには残りの８０％が供給さ
れることになりその分、走行速度が減少して同時操作性
を低下させる欠点がある。Tables 1 (b) and (c) are diagrams showing the conventional technology, and as shown in (b), the discharge amount of the hydraulic pump l is adjusted by
4b, and if you operate the work equipment as shown in (C) to supply 20% of the discharge amount of the hydraulic pump 1, the remaining 80% will be delivered to the left and right travel motors. This has the disadvantage that the running speed decreases and the simultaneous operation efficiency decreases accordingly.
（発明の効果）
以上詳述したごとく、本発明によるときは次のような効
果を得ることができる。(Effects of the Invention) As detailed above, according to the present invention, the following effects can be obtained.
（１）ロードセンシング弁の差圧設定ばねのばね力を複
数段に切換えるようにすれば、同じ走行操作弁の操作量
（開度）；Ａに対して複数段の油圧ポンプ吐出量；Ｑ、
言い換えれば、複数段の走行速度が得られるため、オペ
レータが作業状況、路面状況に応じて最適な速度段が選
び易くなる。(1) If the spring force of the differential pressure setting spring of the load sensing valve is switched to multiple stages, the hydraulic pump discharge amount of multiple stages; Q, for the same traveling operation valve operation amount (opening degree);
In other words, since a plurality of traveling speeds can be obtained, it becomes easier for the operator to select the optimum speed stage according to the work situation and road surface condition.
（２）走行モータの容量を二段に切換えるようにすれば
、前記ロードセンシング弁の差圧設定ばねのばね力の切
換による複数段の走行速度段は２倍になり、更に、作業
状況、路面状況に応じてオペレータが最適な速度段を選
び易くなる。(2) If the capacity of the travel motor is switched to two stages, the number of travel speed stages by switching the spring force of the differential pressure setting spring of the load sensing valve will be doubled. This makes it easier for the operator to select the optimal speed stage depending on the situation.
（３）車両走行中は油圧ポンプの吐出油量が最大となら
ないよう余裕を持たせて設定されているため、車両走行
中に作業機を操作しても車両の走行速度が低下して荷揺
れ等の発生を防止することができ、同時操作性を向上す
ることができる。(3) The hydraulic pump is set with a margin so that the amount of oil discharged from the hydraulic pump does not reach its maximum level while the vehicle is running, so even if the work equipment is operated while the vehicle is running, the running speed of the vehicle will decrease and the load will sway. It is possible to prevent the occurrence of such problems, and it is possible to improve simultaneous operability.
！＃１図は油圧掘削機の走行速度制御装置に適用された
本発明の実施例を示す図、第２図は本発明の実施例と従
来の技術を比較するための油圧ポンプの吐出量と吐出油
圧の関係を示す図、第３図は従来の技術を示す図である
。
１ ・ ・ ・ ・ ・
１ ａ ・ ・ ・ ・
２ａ、２ｂ ・
４ａ、４ｂ ・
５ ・
６ ・
７ ・
８ ・
９ ・
９ ｂ ・
１１ ・
・油圧ポンプ
・油圧ポンプ容量制御シリンダ
・走行操作弁
・走行モータ
・走行モータ速度切換スイッチ
・制御圧切換弁
・コントローラ
・制御ポンプ
・ばね力調整シリンダ
・ピストンロッド
・ロードセンシング弁
１１ａ・・・・・・差圧設定ばね
１１ｂ・・・・・・Ｉ１１パイロットシリンダ１１ｃ・
・・・・・第２パイロットシリンダ１２・・・・・・・
制御圧切換弁
１３ａ、１３ｂ・・走行モータ容量切換弁１４ ａ、
１４ ｂ・・・パイロットシリンダ１５・・・・・・
・走行モータ容量制御シリンダ２０ａ、２０ｂ・・カウ
ンタバランス弁２１・・・・・・・チエツク弁! Figure #1 is a diagram showing an embodiment of the present invention applied to a traveling speed control device of a hydraulic excavator, and Figure 2 is a diagram showing the discharge amount and discharge of a hydraulic pump for comparing the embodiment of the present invention and conventional technology. FIG. 3, which is a diagram showing the relationship of oil pressure, is a diagram showing a conventional technique. 1 ・ ・ ・ ・ ・ 1 a ・ ・ ・ 2a, 2b ・ 4a, 4b ・ 5 ・ 6 ・ 7 ・ 8 ・ 9 ・ 9 b ・ 11 ・ ・Hydraulic pump, hydraulic pump capacity control cylinder, travel operation valve, travel Motor/travel motor speed switching switch/control pressure switching valve/controller/control pump/spring force adjustment cylinder/piston rod/load sensing valve 11a...differential pressure setting spring 11b...I11 pilot cylinder 11c・
...Second pilot cylinder 12...
Control pressure switching valves 13a, 13b...Travel motor capacity switching valve 14a,
14 b... Pilot cylinder 15...
・Travel motor capacity control cylinders 20a, 20b...Counter balance valve 21...Check valve
Claims (3)
御して、左右の走行モータへ供給するようになし、前記
油圧ポンプの容量制御シリンダの制御圧をコントロール
するロードセンシング弁の第１パイロット室に前記油圧
ポンプの吐出油圧を導くと共に、第２パイロット室に走
行モータの駆動圧を導き、前記第１パイロット室の推力
と、第２パイロット室の推力および差圧設定ばねのばね
力との釣合いによって、前記油圧ポンプの容量制御シリ
ンダの制御圧をコントロールするようにした油圧掘削機
の走行速度制御装置において、前記差圧設定ばねのセッ
ト力を複数段に切換える差圧設定ばねのセット力調整装
置を設けたことを特徴とする油圧掘削機の走行速度切換
装置。(1) The first pilot of the load sensing valve controls the discharge oil of the hydraulic pump by the left and right travel operation valves and supplies it to the left and right travel motors, and controls the control pressure of the capacity control cylinder of the hydraulic pump. The discharge hydraulic pressure of the hydraulic pump is introduced into the chamber, and the drive pressure of the travel motor is introduced into the second pilot chamber, so that the thrust of the first pilot chamber, the thrust of the second pilot chamber, and the spring force of the differential pressure setting spring are combined. In a traveling speed control device for a hydraulic excavator, the control pressure of a capacity control cylinder of the hydraulic pump is controlled by balance, and the setting force of the differential pressure setting spring is adjusted to switch the setting force of the differential pressure setting spring to a plurality of stages. A traveling speed switching device for a hydraulic excavator, characterized in that the device is provided with the device.
量を二段に切換えるための走行モータ容量切換装置を設
けたことを特徴とする油圧掘削機の走行速度切換装置。(2) The travel speed switching device for a hydraulic excavator according to claim (1), further comprising a travel motor capacity switching device for switching the travel motor capacity in two stages.
セット力調整装置あるいは走行モータの容量切換装置を
、ソレノイド弁により制御油圧源およびタンクに選択的
に接続することを特徴とする油圧掘削機の走行速度切換
装置。(3) In claim (2), the setting force adjusting device for the differential pressure setting spring or the capacity switching device for the travel motor is selectively connected to the control hydraulic pressure source and the tank by a solenoid valve. Travel speed switching device for hydraulic excavators.
Priority Applications (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2009762A JP2520314B2 (en) | 1990-01-18 | 1990-01-18 | Travel speed switching device for hydraulic excavator |
| DE69120254T DE69120254T2 (en) | 1990-01-18 | 1991-01-17 | SYSTEM FOR CHANGING THE SPEED OF A HYDRAULIC EXCAVATOR |
| US07/910,261 US5331812A (en) | 1990-01-18 | 1991-01-17 | Traveling speed changeover device for hydraulic excavator |
| PCT/JP1991/000043 WO1991010784A1 (en) | 1990-01-18 | 1991-01-17 | System for changing over running speed of hydraulic excavator |
| EP91902759A EP0511387B1 (en) | 1990-01-18 | 1991-01-17 | System for changing over running speed of hydraulic excavator |
| KR1019920701621A KR0141976B1 (en) | 1990-01-18 | 1991-01-17 | Driving velocity changing device for hydraulic pressure system of excavator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2009762A JP2520314B2 (en) | 1990-01-18 | 1990-01-18 | Travel speed switching device for hydraulic excavator |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03212523A true JPH03212523A (en) | 1991-09-18 |
| JP2520314B2 JP2520314B2 (en) | 1996-07-31 |
Family
ID=11729288
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2009762A Expired - Lifetime JP2520314B2 (en) | 1990-01-18 | 1990-01-18 | Travel speed switching device for hydraulic excavator |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US5331812A (en) |
| EP (1) | EP0511387B1 (en) |
| JP (1) | JP2520314B2 (en) |
| KR (1) | KR0141976B1 (en) |
| DE (1) | DE69120254T2 (en) |
| WO (1) | WO1991010784A1 (en) |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2250108B (en) * | 1990-10-31 | 1995-02-08 | Samsung Heavy Ind | Control system for automatically controlling actuators of an excavator |
| DE4307872C2 (en) * | 1993-03-12 | 2001-05-17 | Orenstein & Koppel Ag | Load pressure-independent control of the speed of hydraulic control elements |
| US5553453A (en) * | 1995-05-18 | 1996-09-10 | Caterpillar, Inc. | Method for providing different speed ranges for a speed pedal |
| WO1997010457A1 (en) * | 1995-09-11 | 1997-03-20 | O & K Mining Gmbh | Method and device for load-dependent automatic change-over of travelling motors |
| JP2002087336A (en) * | 2000-09-21 | 2002-03-27 | Kobelco Contstruction Machinery Ltd | Construction machine with speed change-over function |
| US20030230083A1 (en) * | 2002-06-14 | 2003-12-18 | John Dorscht | Continuously variable torque shredder drive |
| KR101155718B1 (en) * | 2004-12-31 | 2012-06-12 | 두산인프라코어 주식회사 | An apparatus for controlling the starting speed of an excavator |
| US7571605B2 (en) * | 2007-01-03 | 2009-08-11 | Clark Equipment Company | Synchronized speed shifting of multiple motors |
| DE102010009704A1 (en) * | 2010-03-01 | 2011-09-01 | Robert Bosch Gmbh | Hydraulic drive and method for controlling such a drive |
| WO2013032370A1 (en) * | 2011-08-26 | 2013-03-07 | Volvo Construction Equipment Ab | Drive control method and system for operating a hydraulic driven work machine |
| CN102359587B (en) * | 2011-08-31 | 2014-03-05 | 贵州詹阳动力重工有限公司 | Manual and automatic integrated speed change system for wheel type hydraulic excavator |
| KR102597793B1 (en) * | 2016-11-02 | 2023-11-03 | 에이치디현대인프라코어 주식회사 | Excavator |
| CN106763743B (en) * | 2016-12-26 | 2019-02-12 | 潍柴动力股份有限公司 | A kind of mobile gear-shifting control method of hydrostatic transmissions and system |
| JP6959905B2 (en) * | 2018-11-29 | 2021-11-05 | 日立建機株式会社 | Hydraulic drive |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3203165A (en) * | 1962-08-10 | 1965-08-31 | New York Air Brake Co | Hydraulic device |
| JPS5326553Y2 (en) * | 1972-12-21 | 1978-07-06 | ||
| JPS49100090A (en) * | 1973-01-30 | 1974-09-20 | ||
| JPS59106333A (en) * | 1982-12-09 | 1984-06-20 | Daikin Ind Ltd | Rotary body drive hydraulic circuit |
| DE3340332C2 (en) * | 1983-11-08 | 1988-11-10 | Hydromatik GmbH, 7915 Elchingen | Power control device for a hydrostatic drive with flow rate adjustment |
| KR920010875B1 (en) * | 1988-06-29 | 1992-12-19 | 히다찌 겐끼 가부시기가이샤 | Hydraulic drive system |
| KR940010867B1 (en) * | 1989-01-27 | 1994-11-18 | 히다찌 겐끼 가부시기가이샤 | Hydraulic driving running apparatus |
| KR940009219B1 (en) * | 1989-03-30 | 1994-10-01 | 히다찌 겐끼 가부시기가이샤 | Hydraulic driving apparatus of caterpillar vehicle |
-
1990
- 1990-01-18 JP JP2009762A patent/JP2520314B2/en not_active Expired - Lifetime
-
1991
- 1991-01-17 KR KR1019920701621A patent/KR0141976B1/en not_active IP Right Cessation
- 1991-01-17 EP EP91902759A patent/EP0511387B1/en not_active Expired - Lifetime
- 1991-01-17 US US07/910,261 patent/US5331812A/en not_active Expired - Lifetime
- 1991-01-17 WO PCT/JP1991/000043 patent/WO1991010784A1/en active IP Right Grant
- 1991-01-17 DE DE69120254T patent/DE69120254T2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| WO1991010784A1 (en) | 1991-07-25 |
| EP0511387A1 (en) | 1992-11-04 |
| KR920703939A (en) | 1992-12-18 |
| EP0511387B1 (en) | 1996-06-12 |
| KR0141976B1 (en) | 1999-02-18 |
| DE69120254T2 (en) | 1996-10-10 |
| EP0511387A4 (en) | 1993-04-07 |
| US5331812A (en) | 1994-07-26 |
| JP2520314B2 (en) | 1996-07-31 |
| DE69120254D1 (en) | 1996-07-18 |
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